1. Field of the Invention
The present invention is directed to apparatuses for connecting and disconnecting tubular members (e.g. casing, tubing, pipe, or drill pipe) and, in certain particular aspects to iron roughnecks, tongs, and methods of their use.
2. Description of Related Art
“Iron roughnecks,” combine a torque wrench and a spinning wrench to connect and disconnect tubulars, e.g. drilling components, e.g. drill pipe, in running a string of tubulars into or out of a well. Prior art iron roughnecks are shown. e.g., in U.S. Pat. Nos. 4,023,449, 4,348,920, 4,765,401, 6,776,070, all of which are incorporated herein by reference in their entirety.
Various prior art iron roughnecks have a spinning wrench and a torque wrench mounted together on a carriage. For making or breaking threaded connections between two tubulars, e.g. joints of drill pipe, certain iron roughnecks have a torque wrench with two jaw levels. An upper jaw of the torque wrench is used to clamp onto a portion of an upper tubular, and a lower jaw clamps onto a portion of a lower tubular, e.g. upper and lower threadedly connected pieces of drill pipe. After clamping onto a tubular, the upper and lower jaws are turned relative to each other to break or make a connection between the upper and lower tubulars. A spinning wrench, mounted on the carriage above the torque wrench, engages the upper tubular and spins it until it is disconnected from the lower tubular (or in a connection operation, spins two tubulars together prior to final make-up by the torque wrench).
Certain iron roughnecks are mounted for movement from a wellbore center to a retracted position which does not interfere with or block performance of other operations relative to the well and rotating or driving apparatuses. Such a prior art system can be used for making and breaking joints in a main string or for connecting to or disconnecting from a tubular section located apart from a wellbore center, e.g. in a mousehole (or rathole) at a side of a well.
Certain prior art iron roughneck systems include a carriage for rolling on the surface of the rig floor along a predetermined path. In certain prior art systems a spinner and torque wrench are mounted for upward and downward movement relative to a carriage, for proper engagement with tubulars, and for tilting movement between a position in which their axis extends directly vertically for engagement with a vertical well pipe and a position in which the axis of the spinner and torque wrench is disposed at a slight angle to true vertical to engage and act against a pipe in an inclined mousehole. In certain prior art systems, a spinner is movable vertically with respect to a torque wrench.
With a variety of non-shouldering connections, including, but not limited to, wedge thread connections, various prior art iron roughnecks are able to rotate a tubular through an arc ranging between about 28° and 30°. However, accurate full make up of a joint between two non-shouldering connections often requires that one tubular be rotated more than 30° to form a good connection. In order to provide the additional rotation, these prior art systems have to unclamp, re-position jaws, clamp again, and rotate again (and, perhaps, do this several times).
Several prior art iron roughnecks and tongs can distort or damage thin-walled tubulars due to the fact that they employ two opposed jaws to clamp a tubular. With other prior art systems, a spinner may spin a tubular's pin end into a box, but, due to a relatively long tapered pin desired shouldering of the connection may not be achieved and re-clamping of the tubulars with the torque wrench and again rotating one of the tubulars may be required.
The prior art discloses a variety of tongs for use in wellbore operations, e.g., but not limited to, as disclosed in and referred to in U.S. Pat. Nos. 6,684,737; 6,971,283; 5,161,438; 5,159,860; 5,842,390; 5,245,877; 5,259,275; 5,390,568; 4,346,629; 5,044,232; 5,081,888; 5,167,173; 5,207,128; 5,409,280; 5,868,045; 6,966,385; 6,138,529; 4,082,017; 6,082,224; 6,213,216; 6,330,911; 6,668,684; 6,752,044; 6,318,214; and 6,142,041. Several prior art tongs employ two opposed grippers which apply forces to a tubular in such a manner that the tubular can be distorted or damaged.
There is a need, recognized by the present inventors, for an effective and efficient tubular gripping system which minimizes distortion of a tubular.
There is a need, recognized by the present inventors, for an effective and efficient iron roughnecks and tongs which can operate on a wide variety of tubulars.
There is a need, recognized by the present inventors, for an effective and efficient iron roughnecks and tongs which can finalize a threaded connection with a minimum of clamping steps.